Apparatus for applying a substance to a road surface



P 1963 H. BURKHARD 3,102,731

APPARATUS FOR APPLYING A SUBSTANCE TO- A ROAD SURFACE Filed May 15, 1961 3 Sheets-Sheet 1 g &

-O f. 4 g r k g m 3 FN 9' co P 3, 1963 H. BURKHARD 3,102,731

APPARATUS FOR APPLYING A SUBSTANCE TO A ROAD SURFACE Filed May 15, 1961 5 Sheets-Sheet 2 Sept. 3, 1963 H. BURKHARD 3,102,

APPARATUS FOR APPLYING A SUBSTANCE TO A ROAD SURFACE Filed May 15, 1961 3 Sheets-Sheet 3 FIGA United States Patent 3,102,731 APPARATUS FOR APPLYING A SUBSTANCE TO A ROAD SURFACE Hans Burkhard, 1t) Meiurad-Lienert-Strasse, Zurich, Switzerland Filed May 15, 1961, Ser. No. 110,009 Claims priority, application Switzerland May 16, was Claims. (Cl. 275-7) The present invention relates to an apparatus for applying a substance to a road surface, and more particularly to an apparatus carried by a carriage means for uniformly distributing a dispersible substance, such as sand or salt over a road surface.

It is the main object of the present invention to provide apparatus capable of uniformly distributing a substance over a road surface regardless of the speed of movement of the carriage on which it is mounted, and regardless of the Width of the strip of the road surface over which the substance is distributed.

Another object of the present invention is to dispense amounts of the substance which are related to the speed of the carriage on which the apparatus is mounted.

Another object of the present invention is to adjust the amount of the discharged substance in accordance with the width of the road surface over which it is distributed.

Another object of the present invention is to use a stream of air for throwing the substance against distributing means which are adjustable to distribute the sub stance over strips of the road surface of different width.

Other objects of the apparatus of the invention will become apparent from the following description of a preferred embodiment of the invention.

One apparatus according to the present invention comprises a carriage; air moving means on the carriage; supply means, preferably including means for dispensing selected amounts of a dispersible substance for discharging the same into the air stream produced by the air moving means; and distributing means located in the air stream for distributing the substance conveyed by the same over the road surface. The distributing means preferably include .a pair of adjustable distributing arms which can be moved between a contracted position and a spread position covering a Wider strip of the road surface.

The dispensing means is preferably a conveyor screw with adjustable blades permitting a change of the dispensed amount. The conveyor screw is driven from a road engaging drive member so that the amount of the substance discharged into the air stream depends on the speed of the carriage on which the apparatus is mounted. Such carriage may be a trailer, or a self-propelled vehicle. In one embodiment of the invention, the distributing arms and the blades of the conveyor screw are simultaneously adjusted by the operator so that the conveyor supplies a greater amount of the dispersible substance into the air stream when the distributing means are adjusted to distribute the substance over a wider strip of the road surface.

It is advantageous to provide means for stopping the conveyor when the blower motor stops, since in this manner direct discharge of the substance onto the road surface in undistr-ibuted and undispersed condition is prevented.

In one embodiment of the invention, the apparatus is mounted on an auxiliary frame permitting a turning of the apparatus to a position in which the distributing means are located at the center line of the road surface, while the carriage drives along the right hand lane.

Preferably, a vibrator means is provided for vibrating a container from which the .dispersible substance is sup- "Ice 2 plied to the metering conveyor so that the dispersible substance is supplied in loose condition to the conveyor screw.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accornpnaying drawings, in which:

FIG. 1 is a side view illustrating an apparatus according to the invention mounted on a trailer;

FIG. 2 is .a plan view of the apparatus shown in FIG. 1, partially in section to omit certain elements for the sake of clarity;

FIG. 3 is :a side elevation illustrating vibrator means for the sup-ply holding container on an enlarged scale;

FIG. 4 is a front view of the device shown in FIG. 3; and

FIG. 5 is a sectional view showing a part of the apparatus on an enlarged scale.

Referring now to the drawings, and more particularly to FIGS. 1 and 2., a carriage means 1 in the form of a trailer having a linkage means 2 at the front end, and running on a pair of wheels 4, supports a mast 5 turnable about a vertical axis and provided with a manually operated winch 6 for Winding up a rope or cable 7 terminating in a hook :8.

By operation of this crane, a container 9 can be picked up from a position located on the side of carriage means I, raised, and deposited in the illustrated position on an annular support 11 through which a neck portion of the container 9 downwardly projects. The support 11 is constructed as a frame, as best seen in FIGS. 3 and 4. A vibrator ring i2 surrounds the projecting neck portion 10 of the container, not shown in FIGS. 3 and 4, so that upon vibration of ring 42, the container is vibrated whereby a dispersible granulated substance, for example salt or sand, is loosened so :as to freely flow through the open end of neck portion 10 of container 9 which preferably is made of a flexible material such as a synthetic plastic.

The neck 10 projects into the region of a tubular inlet of a casing 12 which surrounds a conveyor screw means 13. Conveyor screw means 13 has a tubular shaft 13 on which blades 14- are mounted for turning movement between positions extending perpendicular to the axis of rotation of shaft 13', and a plurality of positions inclined at different angles to the axis of shaft 13, so that the blades 14 form in one posit-ion a continuous helix,

and have a plurality of intermediate portions in which the pitch angle of the blades is different from the pitch angle of the helix. The blades 14 are adjusted by adjusting means including a rod 15 which extends into the tubular shaft 13" and is shiftable in the same in axial direction. Rod 15 has recesses 51 which are spaced from each other in axial and circumferential directions. A stud 52 is mounted in each recess 51. Each blade 14 has a cylindrical root portion mounted for turning movement in a bearing 54 which is fixed in an opening of tubular shaft 13'. A plate 55 with a guide slot is secured to each root member 53, and the guide slot has one end in the region of the turning axis of the respective blade 14, and the other end radially spaced therefrom. Stud 52 is located at the outer end of the respective guide slot 56', as best seen in the center portion of FIG. 5. When rod 15 is shifted in axial direction, plate 55 is turned with blade means 53, 14 from the position A to the position B shown in chain lines in FIG. 5. In the position B, the blades form a continuous helix, and in the 7 line.

a 3 position A the blades are located perpendicularly to the axis of shaft 13'. Rod 15 projects out of casing 12 and has a vertical slide member located in a bifurcated arm 40a of a lever '40 which has another bifurcated arm 4% in which a slide member 29a of a rod 29' is slidably mounted. The left end of rod 29, as viewed in the drawing, is connected by a linkage means, not shown, to .a manually operated lever which is under control of the operator. When this lever is shifted by the operator, lever 46 is turned about its fulcrum on a lever 49c, whereby the angle of blades 14, and the amount conveyed by conveyor screw 13, 14 is adjusted. It is evident that in the position of blades 14 in which they extend perpendicular to the axis of shaft 13', the substance falling from container 9 into casing 12, will not be conveyed to the end portion 18 of casing 12 which is flanged to a long tubular guide means 17 which is supported on the carriage frame and supports the conveyor casing 12. The front end of the tubular guide means 17 is secured to the outlet flange 20 of a blower means 21 which is driven by a gasoline engine 22. A supporting arm 26 is secured to the rear end 23 of the tubular guide means 1-7 and has a slot 26a in which a slide block of a control bar 28 is guided. Control bar 28 has two slots 27 in which slide blocks 24a of a pair Y of distributing arms '24 are mounted. A pivot means 24b supports the forward ends of distributing arms 24 for turning movement between a contracted position spaced a small angle and a spread position shown in broken The rear end of rod 29 is articulated to the center of control bar 28. When rod 29 is shifted in the direction of arrow 30 by the operator, control bar 28 is also shifted, and effects turning movement of the distributing arms 24 in the directions of the arrows 31 and 32. A substantially semi-circular downwardly curving hood 41 is mounted on support arm 26 above the distributing arms 24. The cross section of the distributing arms is arcuate, and preferably substantially semi-circular. Distributing arms 24 and pivot means 24b are disposed to lie directly in teh air stream blown by air moving means 21 into the tubular guide means 17 and out of the open rear end 23. As clearly shown in FIG. 2, distributing arm 24 moves symmetrically to a vertical plane of symmetry passing through the axis 25 of tubular guide means 17 and through the axis of the tubular casing 12.

When a dispersible substance is supplied through neck of container 9 into the tubular casing 12 it is conveyed by the conveyor screw 13, 14 so that a selectable amount of the dispersible substance passes through the tubular connection 19 into the air stream in the tubular guide means 17 and is blown against the distributing arms 24. Depending on the position of these arms, a wider or narrower strip of the road surface will be covered with the disperisble substance.

The drive means for the dispensing conveyor 13, are driven from a wheel 33 turnably mounted on a supporting arm 33 which is pivotally supported on frame 3 by a pivot means 39. A spring, not shown, urges supporting arm 28 downward so that the wheel 33 tends to engage the road surface. However, it is possible to retract wheel 33 to an inoperative position by conventional means, not shown in the drawing. A chain wheel is secured to the axle of wheel 33 and drives through a chain 34 another chain wheel which is secured to one coupling part of an electromagnetic coupling means 35. The other coupling part is connected by bevel gears to shaft 13 so that the conveyor screw is driven from wheel 33 through a transmission including a chain drive and the coupling means 35. The speed of the conveyor screw will depend on the speed of the carriage means on which the rotary speed of wheel 33- depends.

The electromagnetic coupling means 35 is constructed in such a manner that it is in its coupling position as long as it is energized. The winding of the electromagnetic the coupling 35 moves automatically to a disconnecting position in which the conveyor screw is not driven, al-

though wheel 33 may continue to roll on the ground during further carriage movement. Since the amount of the dispersible substance discharged by the dispensing conveyor 12, 13, 14 depends on the rotary speed of the conveyor screw 13, 14, more dispersible material will be discharged into the air stream in tubular guide means 17 when the carriage moves fast than when the carriage moves slow. 'Consequently, the distributed amount of the substance per unit of length of the road is constant. This constant amount of the dispersible substance discharged per unit length of the road surface, is determined by setting the conveyor blades 14 by operation of rod 29 and lever 40.

Operation of control rod 29 for this purpose will also effect an angular movement of the distributing arms 24. When the discharged amount of the substance is increased, arms 24 are wider spread to distribute such greater amount over a wider strip of the road surface.

When fulcrum 400 of lever 40 is shifted in the direction of the arrows, the effective radii of the lever arms 40a and 40b relative to the slides 37, 29 are adjusted, and have a different ratio. In this manner, the specific amount of the dispersible susbtance discharged per unit length of the road surface can be varied for a constant width of the strip of the road surface over which the distributing arms 24 distribute the substance. It will be appreciated that the amount of dispersed substance can be adjusted without any effort to the specific requirements of the distributed substance, which may be salt or sand, to the width of the road surface, and to the amount desired to be distributed over a given area of the road surface.

Certain substances have a tendency to cake in container 9, and it is advantageous to provide a vibrator arrangement for maintaining the susbtan'ce in loose condition in container 9. The vibrator ring 44 is mounted on a pivot means 49 on the annular support 11 and positioned to encircle the neck portion 10 of a container 9 placed in the annular support 11, as best seen in FIGS. 3 and 4. A lever 43 has a free end in contact with vibrator ring 42 and is guided in a guide means 44. The lower end of lever 43 is articulated to another lever 45 which is rockably mounted on a pivot means 46. A cam follower portion 47 of lever 45 is urged by the weight of vibrator ring 42 into engagement with the rotary cam 48 which is driven from coupling means 35 together with shaft 13. As long as shaft 13' is driven by the energized coupling means 35, ring 42 is vibrated by the oscillating lever system 45, 43, so that the contents of container 9 freely flow into the inlet of casing 12 to be conveyed by the conveyor screw 13, 14.

Blower means 21, motor 22, generator 36, tubular guide means 17 with support arm 26 of distributor means 24, 41 are preferably mounted on an auxiliary frame which is turnable about a vertical axis on the main frame of the carriage. In this manner, the pivot means 241) of the distributing arm 24 can be placed at the center line of the road, While the carriage moves in the right hand lane, permitting a distribution of the dispersible substance over the entire road surface without the carriage having to straddle the dividing line. A lateral displacement of the distributing means is also advantageous when strong lateral winds tend to displace the substance distributed by the distributing arms 24.

During rapid movement of the carriage, a certain suction is created behind the rear end of the carriage, which may have a detrimental eflect on the uniform distribution of the substance. The hood 41 protects the distributing means from such air turbulence so that it is properly distributed over the road surface. The strong pressure of the air stream discharged from tubular guide means 17 is, however, sufiicient to obtain a uniform distribution, even if the hood 41 is not provided.

The apparatus is operated in the following manner: If the carriage is a trailer, as illustrated, it is coupled to a self-propelled cab and driven along the road. The container 9 is in the illustrated position, with its neck 10 supported on ring 11 and extending into the inlet of the conveyor casing 12 so that the dispersible substance flows into the same. Motor 22 is started, and blower means 21 blows air through the tubular guide means 17 in a stream toward the distributing arms 24. Generator 36 is driven and energizes coupling means 35. The effective lengths of lever arms 40a and 4% are adjusted in accordance with the nature of the dispersed substance and the desired amount of the substance to be distributed over a unit area of the road surface.

Supporting arm 38 is released and wheel 33 engages the road so that during movement of the carriage, conveyor screw 13, 14- is rotated and transports measured amounts of the substance towund outlet means 19 from where they fall into the air stream in the guide means 17 and are blown against the distributing arms 24. The substance slides outwardly along the angularly spaced distributor arms 24, [and is distributed over a corresponding strip of the road surface. The amount of the substance distributed during a time unit depends on the speed of the carriage on which the speed of the conveyor screw 13, 14 depends.

When the operator shifts rod 29 in the direction of the arrow 30, the amount of the substance discharged by the conveyor means 13, 14- is varied in accordance with the position of the distributing arms 24 so that a greater amount of the substance is blown at the distributor arms 24 when the same are in such a spread position as to cover a wider strip of the road surface. Due to the fact that the drive wheel 33 is arranged :at the center of the apparatus, curves in the road have very little influence on the speed of wheel 33, and on the distributed amount of the substance. If the width of the road varies, the operator actuates rod 29 to vary the position of the distributor arms 24 so that the same distribute the substance only over the road surface, not on the shoulders. If a narrower part of the road is to be covered with the substance, the retraction of the distributing arm 24* will also effect adjustment of the blades 14 to a position in which the lesser amount of the substance is supplied into the air stream for distribution over the road surface.

If it is desired to apply more, or less, of the substance on road parts having the same width, the position of fulcrum 400 is varied so that in the same position of the distributing arms 24, more or less of the substance is conveyed by conveyor means 13, 14 into the air stream.

In the event that the blower 21, or its motor 22 stops for any reason, the electromagnetic coupling means 35 is deenergized due to the stopping of generator 36, and conveyor screw 13, 14 stops even though wheel 33 continues to be driven during continued movement of the carriage. If the conveyor would not be stopped under these conditions, the substance would be conveyed into the rear end of tubular guide means 17 which are being blown out, which may result in clogging of the tubular guide means 17.

The term road surface as used in the present application is intended to cover any surface on a ground over which a carriage may move apparatus of the type described. The term dispersible substance as used in the present specification is intended to cover granular material, substances consisting of small particles of uniform or different size, powders, liquids, and any other substance suitable to be entrained in an air stream.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of apparatus for applying a substance to a road surface differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus in which an air stream carrying a dispersible material is blown against distributing means so that the substance is distributed over a road surface, it is not intended to be limited to the details shown, since various modifications and structunal changes may *be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. An apparatus for applying a dispersi-ble substance to a road surface, comprising, in combination, carriage means adapted to move on the road surface; blower means supported on the front end of said carriage means for producing a rearwardly directed stream of air along said carriage means; a support on said carriage means for detachably supporting a container for the substance; conveyor means supported on said carriage means and having an inlet for receiving the substance from the container means, an outlet for discharging the dispersib le substance into said air stream for convection by the same, and a conveyor screw means between said inlet and outlet having an axis of rotation and blades adjustable between an inoperative position extending perpendicular to said axis and a plurality of conveying positions inclined at different angles to said axis whereby different amounts of the substance are discharged through said outlet in said conveying positions; manually operated adjusting means connected to said blades: for moving the same between said positions thereof; distributing means including a pair of distributor arms disposed on the rear end of said carriage means in the path of the conveyed substance and being mounted for turning movement about a vertical axis between a contracted position angularly spaced a small angle to cover a narrow portion of the road surface, and a spread position angularly spaced a greater angle to cover a wide portion of the road surface; manually operated adjusting means connected to said distributing arms for moving the same between said contnacted and spread positions whereby the substance is distributed over narrower or wider areas of the road surface; and connecting linkage means connecting said adjusting means for said blades with said adjusting means for said distributing arms so that the same are simultaneously adjusted by an operator whereby the position of said dispensing arms corresponds to the amount of the substance discharged by said conveyor screw through said outlet.

2. An apparatus as set forth in claim. 1 wherein said connecting linkage means includes manually adjustable control means for varying the ratio of the adjustments of said adjusting means for said blades and of said adjusting means for said distributing arms.

3. An apparatus as set forth in claim 1 and including a hood mounted on said carriage means. above said distributing arms for shielding the same and the substance distributed by the same from air turbulence developed at the rear end of said carriage means.

4. An apparatus for applying a dispersible substance to a road surface, comprising, in combination, carriage means adapted to move on the road surface; blower means supported on the front end of said carriage means for producing a rearwardly directed stream of air along said carriage means; a motor for driving said blower means; a generator driven by said motor, tubular guide means for guiding said stream of air and longitudinally disposed on said carriagemeans rearwardly of said blower means; a support on said carriage means for detachably supporting a container for the substance; conveyor means supported on said carriage means and having an inlet for receiving the substance from the container means, an outlet for discharging the dispersible substance into said tubular guide means and into said air stream for convection by the same, and a conveyer screw means between said inlet and outlet having an axis of rotation and blades adjustable between an inoperative position extending perpendicular to said axis and a plurality of conveying positions inclined at diflerent angles to said axis whereby different amounts of the substance are discharged through said outlet in said conveying positions; manually operated adjusting means connected to said blades for moving the same between said positions thereof; drive means for said conveyor screw means including a road-engaging wheel, a supporting arm turnably supporting said wheel and being mounted on said carriage means for movement between an operative position in which said wheel is adapted to engage the road surface and an inoperative position in which said wheel is retracted from the road surface, transmission means connecting said wheel with said conveyor screw so that the same is rotated at a speed related to the speed of movement of said carriage means and said wheel along the road surface, said transmission means including an electromagnetic coupling means electrically connected to said generator so as to be energized during operation of said motor whereby said coupling means is in a coupling position during operation of said blower means and disconnects said conveyer screw means from said drive means when said blower means stops, and means for urging said supporting arm to said operative position; distributing means including a pair of distributor arms disposed on the rear end of said carriage means aligned with said tubular guide means in the path of the conveyed substance and beingmounted for turning movement about a vertical axis between a contracted position angularly spaced at small angle to cover a narrow portion of the road surface, and

a spread position angularly spaced a greater angle to cover a Wide portion of the road surface; manually operated adjusting means connected to said distributing arms for moving the same between said contracted and spread positions whereby the substance is distributed over narrower or wider areas of the road surface; and connecting linkage means connecting said adjusting means for said blades with said adjusting means for said distributing ZLIIHS so that the same are simultaneously adjusted by an operator whereby the position of said dispensing arms corresponds to the amount of the substance discharged by said conveyor screw through said outlet.

5. An apparatus for applying a dispersible substance to a road surface, comprising, in combination, carriage means adapted to move on the road surface blower means supported on the front end of said carriage means for producing a rearwardly directed stream of air along said carriage means; a motor for driving said blower means; a generator driven by said motor; a support on said carriage means for detachably supporting a container for the substance; conveyer means supported on said carriage means and having an inlet for receiving the substance from the container means, an outlet for discharging the dispersible substance into said air stream for convection by the same, and a conveyor screw means between said inlet and outlet having an axis of rotation and blades adjustable between an inoperative position extending perpendicular to said axis and a plurality of conveying positions inclined at ditferent angles to said axis whereby different amounts of the substance are discharged through said outlet in said conveying positions; manually operated adjusting means connected to said blades for moving the same between said positions thereof; drive means for said conveyer screw means including a road-engaging wheel, a supporting arm turnably supporting said wheel and being mounted on said carriage means for movement between an operative position in which said wheel is adapted to engage the road surface and an inoperative position in which said wheel is retracted from the road surface, transmission means connecting said wheel with said conveyer screw so that the same is rotated at a speed related to the speed of movement of said carriage means and said wheel along the road surface, said transmission means including an electromagnetic coupling means electrically connected to said generator so as to be energized during operation of said motor whereby said coupling means is in a coupling position during operation of said blower means and disconnects said conveyer screw means from said drive means when said blower means stops, and means for urging said supporting arm to said operative position; a vibrator means driven by said drive means through said coupling means and mounted on said support for vibrating a container supported on said support; and distributing means disposed on the rear end of said carriage means in the path of the conveyed substance for distributing the same over the road surface.

References Cited in the file of this patent UNITED STATES PATENTS 613,498 Covington Nov. 1, 1898 772,229 Fairly Oct. 11, 1904 1,282,697 Johnson Oct. 22, 1918 1,987,656 Althouse et a1. a Jan. 15, 1935 2,062,294 Carey et a1 Dec. 1, 1936 2,475,465 Tarrant July 19, 1949 2,893,741 Pilch July 9, 1959 2,923,574 Fuss et al Feb. 2, 1960 

1. AN APPARATUS FOR APPLYING A DISPERSIBLE SUBSTANCE TO A ROAD SURFACE, COMPRISING, IN COMBINATION, CARRIAGE MEANS ADAPTED TO MOVE ON THE ROAD SURFACE; BLOWER MEANS SUPPORTED ON THE FRONT END OF SAID CARRIAGE MEANS FOR PRODUCING A REARWARDLY DIRECTED STREAM OF AIR ALONG SAID CARRIAGE MEANS; A SUPPORT ON SAID CARRIAGE MEANS FOR DETACHABLY SUPPORTING A CONTAINER FOR THE SUBSTANCE; CONVEYOR MEANS SUPPORTED ON SAID CARRIAGE MEANS AND HAVING AN INLET FOR RECEIVING THE SUBSTANCE FROM THE CONTAINER MEANS, AN OUTLET FOR DISCHARGING THE DISPERSIBLE SUBSTANCE INTO SAID AIR STREAM FOR CONVECTION BY THE SAME, AND A CONVEYOR SCREW MEANS BETWEEN SAID INLET AND OUTLET HAVING AN AXIS OF ROTATION AND BLADES ADJUSTABLE BETWEEN AN INOPERATIVE POSITION EXTENDING PERPENDICULAR TO SAID AXIS AND A PLURALITY OF CONVEYING POSITIONS INCLINED AT DIFFERENT ANGLES TO SAID AXIS WHEREBY DIFFERENT AMOUNTS OF THE SUBSTANCE ARE DISCHARGED THROUGH SAID OUTLET IN SAID CONVEYING POSITIONS; MANUALLY OPERATED ADJUSTING MEANS CONNECTED TO SAID BLADES FOR MOVING THE SAME BETWEEN SAID POSITIONS THEREOF; DISTRIBUTING MEANS INCLUDING A PAIR OF DISTRIBUTOR ARMS DISPOSED ON THE REAR END OF SAID CARRIAGE MEANS IN THE PATH OF THE CONVEYED SUBSTANCE AND BEING MOUNTED FOR TURNING MOVEMENT ABOUT A VERTICAL AXIS BETWEEN A CONTRACTED POSITION ANGULARLY SPACED A SMALL ANGLE TO COVER A NARROW PORTION OF THE ROAD SURFACE, AND A SPREAD POSITION ANGULARLY SPACED A GREATER ANGLE TO COVER A WIDE PORTION OF THE ROAD SURFACE; MANUALLY OPERATED ADJUSTING MEANS CONNECTED TO SAID DISTRIBUTING ARMS FOR MOVING THE SAME BETWEEN SAID CONTRACTED AND SPREAD POSITIONS WHEREBY THE SUBSTANCE IS DISTRIBUTED OVER NARROWER OR WIDER AREAS OF THE ROAD SURFACE; AND CONNECTING LINKAGE MEANS CONNECTING SAID ADJUSTING MEANS FOR SAID BLADES WITH SAID ADJUSTING MEANS FOR SAID DISTRIBUTING ARMS SO THAT THE SAME ARE SIMULTANEOUSLY ADJUSTED BY AN OPERATOR WHEREBY THE POSITION OF SAID DISPENSING ARMS CORRESPONDS TO THE AMOUNT OF THE SUBSTANCE DISCHARGED BY SAID CONVEYOR SCREW THROUGH SAID OUTLET. 